In September, we brought you photos of the facelifted MINI 3 Door Hatch being tested in hot John Cooper Works form, and now our spy photographers have followed those up with images of the less aggressive Cooper S 5 Door. The fashionable premium hatch – now four years old – will get few aesthetic tweaks in favour of more comprehensive mechanical upgrades.

We were expecting the cooking One, Cooper and Cooper S models to at least get mildly reprofiled bumpers, but no dice – the Cooper S mule here gets the same front and rear fascias as before. The only changes concern lighting – the LED headlights oval LED projector design previewed on the JCW GP Concept.

Around the back, there are new tail lights, featuring the Union Jack-inspired design found on both the JCW GP and MINI Electric show cars. Also expect an expanded trim and upholstery palette on the inside, plus some revised switchgear and new infotainment systems.

These may seem like incremental changes, but MINI will likely be saving the biggest upgrades under the bonnet. The facelifted Hatch is set to be the first car to receive BMW’s new range of engines announced last year, just as the current car introduced Munich’s then-new modular engine family.

Innovations on petrol engines include an exhaust manifold and turbocharger integrated into the cylinder head, a higher-pressure direct-injection system, new balancer shafts for three-cylinder engines and a quieter single-piece timing chain drive. These changes not only result in an up to 5% reduction in fuel consumption and emissions, but also boost outputs by up to 7 hp and 20 Nm of torque.

This would push power and torque figures on the Cooper S model to 199 hp and 300 Nm, numbers which are nothing to sniff at. A six-speed manual gearbox will almost certainly come as standard, but the current six-speed automatic could either be replaced by the newer eight-speeder from the Clubman and Countryman, or a new seven-speed dual-clutch transmission from the 2017 BMW X1.